Model 3

Description of the model


This third model is again a slight variant of the two first, in which we assign a specific \(\alpha\) to each predator, but we also divide it by the degree of the predator (number of preys). In doing so, we can still isolate difference between predator, to check if some predator seems to be different from the whole, but also try to divide between each of ones predators prey. \[\begin{align} F_{ij}^{real} &= \frac{\alpha_{j}}{D_{j}} * B_i * \frac{B_j}{M_j} \end{align}\]

This model was fit with a hierarchy implemented on the alpha parameter. A global alpha was estimated, with 118 respective unique alphas for each predators. In contrast with model 2, the alphas in model 3 are divided by the predator’s degree.

Summary table

Summary table model 3
mean se_mean sd 2.5% 25% 50% 75% 97.5% n_eff Rhat
a_pop -8.888594 0.0029814 0.3451855 -9.564356 -9.125167 -8.885652 -8.652523 -8.207568 13404.529 1.0002642
a_sd 3.673199 0.0021283 0.2385418 3.244343 3.504178 3.658938 3.831715 4.168994 12562.680 0.9998145
sigma 1.672978 0.0004226 0.0420594 1.592521 1.644661 1.671849 1.700154 1.759202 9906.018 1.0001506

Respective predator alphas

One-one plot of simulation against data